**Factorial**of n is the product of all positive descending integers. Factorial of n is denoted by n!. For Example:

Source GeekforGeeks |

Here, 4! is pronounced as "4 factorial", it is also called "4 bang" or "4 shriek".

The factorial is normally used in Combinations and Permutations (mathematics).

There are many ways to write the factorial program in java language. Let's see the 2 ways to write the factorial program in java.

- Factorial Program using loop
- Factorial Program using recursion

**Factorial Program using loop in java**

```
class FactorialExample{
public static void main(String args[]){
int i,fact=1;
int number=5;//It is the number to calculate factorial
for(i=1;i<=number;i++){
fact=fact*i;
}
System.out.println("Factorial of "+number+" is: "+fact);
}
}
```

**Factorial Program using recursion in java**

```
class FactorialExample2{
static int factorial(int n){
if (n == 0)
return 1;
else
return(n * factorial(n-1));
}
public static void main(String args[]){
int i,fact=1;
int number=4;//It is the number to calculate factorial
fact = factorial(number);
System.out.println("Factorial of "+number+" is: "+fact);
}
}
```

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